QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online September 11, 2009
Journal of Experimental Biology 212, 3142-3147 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.033175

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Hector, C. E. Articles by Johnson, E. C. PubMed PubMed Citation Articles by Hector, C. E. Articles by Johnson, E. C. Social Bookmarking                         What's this?

Functional differences between two CRF-related diuretic hormone receptors in Drosophila

Clare E. Hector^*, Colin A. Bretz^*, Yan Zhao and Erik C. Johnson

Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA

Author for correspondence (johnsoec{at}wfu.edu)

Accepted 29 June 2009

In Drosophila, two related G-protein-coupled receptors are members of the corticotropin releasing factor (CRF) receptor subfamily. We have previously reported that one of these receptors, encoded by CG8422 is a functional receptor for a diuretic hormone, DH₄₄. Here, we report that the other CRF receptor subfamily member, encoded by CG12370, is also a receptor for the DH₄₄ neuropeptide. The lines of evidence to support this identification include increases in cAMP levels due to CG12370 receptor activation and the recruitment of β-arrestin–GFP to the plasma membrane in response to DH₄₄ application. We compared these features of the receptors DH44-R2 (encoded by CG12370) and DH44-R1 (encoded by CG8422) and found fundamental differences in signaling, association with the arrestins, and peptide sensitivity. We found that the sensitivity of DH44-R2 to the DH₄₄ peptide is lower than that of DH44-R1, specifically an estimated EC₅₀ of 7.98E-07 moll^–1 for DH₄₄ by DH44-R2 to an EC₅₀ of 5.12E-09 moll^–1 by DH44-R1 and found that previous reports on the sensitivity of the tubule to DH₄₄ is in agreement with our measurements of DH44-R2 sensitivity. We employed a specific RNAi construct to selectively knock-down DH44-R2 expression and this led to heightened sensitivity to osmotic challenges. The functional characterization of this diuretic hormone receptor in Drosophila demonstrates a high degree of conservation of CRF-like signaling.

Key words: corticotropin releasing factor (CRF), Drosophila melanogaster, diuretic hormone, neuropeptide, G-protein-coupled receptor

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?